PMOD 1907 8 28.8.2013 Carl Dorno founded the PMOD in 1907 The PMOD was located in the Villa Dora until 1976 Carl Dorno 1865-1942

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Dorno rays 9 28.8.2013 The focus of research at the Physikalisch- Meteorologisches Observatorium Davos (PMOD) was the measurement of radiation. In particular: UV radiation, which was later named Dorno Strahlung (Dorno rays is still used in medicine) The measurement platform was on the roof of Villa Dora Most instruments are preserved in the PMOD/WRC archive

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The long path to the creation of the World Radiation Center 10 28.8.2013 1934 workshop at PMOD dedicated to compare pyrheliometers 1956 the Radiation Commission of IAM and the CIMO/WMO Working Group on Radiation held a joint meeting in Davos The main theme of the 1956 meeting was the definition of the Standard Scale of Radiation Conclusion: Need of regular International Pyrheliometer Comparisons...

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1 st International Pyrheliometer Comparison 1959 11 28.8.2013 1934 workshop at PMOD dedicated to compare pyrheliometers 1956 the Radiation Commission of IAM and the CIMO/WMO Working Group on Radiation held a joint meeting in Davos The main theme of the 1956 meeting was the definition of the Standard Scale of Radiation Conclusion: Need of regular International Pyrheliometer Comparisons... IPC I 1959 On the roof of the PMOD, house Dora, Davos Platz Walter Mrikofer director of PMOD 1970 creation of the World Radiation Center in Davos, thanks to the excellent world-wide contacts of Walter Mrikofer to WMO and IRC/IAMAS.

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PMOD/WRC today 12 28.8.2013 PMOD/WRC is a branch of the foundation SFI World Radiation Center since 1971 Operational service Research Calibration of meteorological instruments measuring radiation Development of instruments and methods Energy balance and influence of radiation on the terrestrial climate Green house effect Sun-Earth connection

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International Pyrheliometer Comparison IPC XI 2010 13 The PMOD/WRC is still responsible for the World Radiometric Reference (WRR) and the organization of the IPCs every 5 years. WRR 28.8.2013

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Space experiments are built in house at PMOD/WRC 14 In particular for the measurement of the Total Solar Irradiance, e.g.: 1995 VIRGO/SOHO (PI Claus Frhlich) 2010 PREMOS/PICARD (PI Werner Schmutz) 2015 CLARA/NORSAT-1 28.8.2013

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Total Solar Irradiance measurements in space since 1979 15 28.8.2013 PREMOS is the first fully SI traceable calibrated radiometer in space PREMOS/PICARD is the first fully SI traceable calibrated radiometer in space (SI = International System of Units) PICARD launched 2010

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PREMOS on PICARD 16 28.8.2013 PREMOS is the first fully SI traceable calibrated radiometer in space PREMOS established the absolute value of the Total Solar Irradiance On 27. July 2010 the Total Solar Irradiance was 1360.9 W/m 0.4 W/m 2

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19.1.2010 Why radiation research ? O.5 o C in the last 30 years are antropgenic What is the anthropogenic contribution during the last 100 years? How much is natural warming? 17

TSI monitoring needs to continue 20 28.8.2013 What if the Sun has a Maunder Minimum like minimum in the future? Hypothetical decrease of TSI Solar minimum called Maunder Minimum ongoing scientific discussion and continued need of PMOD/WRC activities !